import javafx.application.Application;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.collections.ObservableList;
import javafx.scene.Node;
import javafx.scene.layout.Pane;
import javafx.scene.shape.Circle;
import javafx.scene.paint.Color;

public class Test extends Application {
	public void start(Stage stage) {
		Pane pane=new Pane();

		Circle circle=new Circle();
		circle.setCenterX(100);
		circle.setCenterY(100);
		circle.setRadius(50);
		circle.setStroke(Color.BLACK);
		circle.setFill(Color.YELLOWGREEN);

		circle.centerXProperty().bind(pane.widthProperty().divide(2));
		circle.centerYProperty().bind(pane.heightProperty().divide(2));

		ObservableList<Node> list=pane.getChildren();
		list.add(circle);

		Scene scene=new Scene(pane,200,200);

		stage.setTitle("show circle");
		stage.setScene(scene);
		stage.show();
	}
}
